Code setting device for signal systems



Sept. 15, 1931. BURDICK 1,823,585

CODE SETTING DEVICE FOR SIGNAL SYSTEMS Filed NOV. 15, 1926 5 Sheets-Sheet l Sept. 15, 1931. H. BURDICK 1,823,585

CODE SETTING DEVICE FOR SIGNAL SYSTEMS Filed Nov. 15, 1926 5 Sheets-Sheet 2 Sept. 15, 1931. BURDlcK 1,823,585

CODE SETTING DEVICE FOR SIGNAL; SYSTEMS Filed 1926 5 Sheets-Sheet 3 70 711 t 13 1 6o l 39 1 OLWJ l w E E '0 n 3] u Sept. 15, 1931. H. BURDICK 1,823,585

CODE SETTING DEVICE FOR SIGNAL SYSTEMS Filed Nov. 15, 1926 5 Sheets-Sheet 4 Sept. 15, 1931. DI 1,823,585

com: SETTING DEVICE FOR SIGNAL SYSTEMS Filed Nov. 15, 1926 5 Sheets-Sheet 5 TEL. WATCH/VAN RELAY POWER lF-erTBurdza/f Patented Sept. 15 1931 UNITED STATES PATENT OFFICE HERBERT BURDICK, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO SIGNAL ENGINEER- ING & MANUFACTURING COMPANY, OF NEW YORK, N. Y., A CORPORATION OI MASSACHUSETTS CODE SETTING DEVICE FOR SIGNAL SYSTEMS Application filed November 15, 1926. Serial No. 148,484.

My present invention relates to an improved code setting device for code signalling apparatus and systems of the type commonly used for controlling, usually from a distance, the operation of various kinds of apparatus, as for instance, apparatus for sounding or displaying a multiplicity of different signals, usually at a multiplicity of stations throughout industrial establishments. Calling and locating individuals and sounding of fire alarm or time signals are well known uses.

The code setting unit in the preferred embodiment comprises, one, two or more units of substantially identical construction, each arranged to determine a distinctive range of code signals. Preferably, each unit has terminals arranged so that the mere juxtaposition or super-position of the several units into a stack disposes said units in an electrically operative assembly without the need for any distinct electrical connecting operations. Preferably the unit or stack of units are disposed upon a support base of corresponding dimensions, through which support base are made the electrical connections to the power circuit, to the code announcing instrument or control relay therefor, as well as to any other associated instruments such as a telephone, a watchmans bell and the like. The circuit from the source of power to the commutator unit is preferably established through registering contact terminals in the base and in the several units of the stack, which register and are in electrical connection in the assembly, so that the circuit may be completed to the commutator unit by disposing the same on a corresponding base with appropriate contacts engaging the corresponding contacts on the uppermost unit of the stack.

The individual units of the stack preferably comprise a rectangular insulating support block along which extend aplurality of parallel bus bars, the ends of which preferably extend outwardly and constitute the terminals previously referred to. The code signal determining keys protrude as a keyboard in front of the frame and key stems integral therewith are mounted in keybar support bracket plates near the front and rear walls of a rectangular frame enclosing the assembly, from the forward face of which the keys protrude. Each key stem has a contact plate facing the bus bars and normally free from contact therewith, said plates and bus bars being so interrelated that upon setting of any key, electric contact is established between the contact plate thereof and those of the bus bars corresponding to the distinctive code signal of the key. In the preferred embodiment, the contact plates on all of the keys are identical and the bus bars have integral spring fingers protruding therefrom and extending in the general direction of the length of the key stems. Two of the bus bars have contacts preferably universal to all of the keys, one of said bus bars determining the original or initial impulse common to all keys and the other universal bus bar determining the circuit for starting the movement hereinbefore referred to of the commutator arm. Contact is made with the comniutator starting bus bar only when the key is in its extreme operative or way-in position, each key being equipped with a spring for returning it after the pressure of the finger is released, to disengage the starting bus bar. A spring urged key or look plate common to all of the keys has notches or slots coacting with a tooth on a depressed key to maintain the same in intermediate or signal operating position after disengagement from the commutator starting bus bar. The depression of any other key releases the lock bar from the previously actuated key, so that the latter will then be cleared.

The preferred embodiment of code setting unit is of a duplex type, including two sets of bus bars and corresponding keys at opposite faces of the insulating support. Preferably, the bus bars are lodged in corresponding grooves in said opposite faces and are fixed in position by rivets, each extending through the insulating support and through bus bars on opposite faces thereof.

The above and other features of my invention may be more fully understood from the following description in connection with the accompanying drawings, in which- Fig. 1 is a perspective view of my code setting apparatus, indicating diagrammatically the conductors from the source of power and to the associated apparatus.

Fig. 2 is a plan view of one of the code setting unit sections, parts thereof being shown in cross-section.

Fig. 3 is a front elevation of one of the code setting sections.

Figs. 4, 5 and 6 are sectional views taken respectively on lines 4-4, 55, and 6-6 of Fi 2.

Fig. 7 is a bottom plan view of the insulating panel bus bar assembly of one of the sectional units, indicating t e position of one of the key contact plates in dot and dash lines.

Fi 8 is a fragmentary view similar to Fig. indicating a portion of another code setting unit.

Fig. 9 is a reverse plan view of one of the ke strips.

Fig. 10 is a. cross-sectional view of a key strip taken on an enlarged scale taken on line 10-10 of Fig. 2.

Fig. 11 is a perspective view of the skeleton binding strap of one of the key setting sections.

Fig. 12 is a plan view of the base unit of the apparatus.

Fig. 13 is a transverse sectional View taken on line 13-13 of Fig. 12.

Fig. 14 is a sectional view on a reduced scale taken on line 14-14 of Fig. 12.

Fig. 15 is a fragmentary sectlonal view of a part of the signalling stack.

Fig. 16 is a developed diagrammatic view illustrating the manner in which the various circuit connections are established between the code setting units and the commutator or code operating unit.

Like reference characters refer to like parts in the different figures.

As indicated diagrammatically in Fig. 1, a preferred installation includes a unit A mounted within reach of the telephone or other operator comprising a generally rectangular box having a plurality of code signalling keys k, each having marked thereon the numerical designation of the code which it controls. Into the base of the unit are led inlet conductors 2' connected to the ordinary electric power and lighting wiring of the building. At the base are also provided outlets for conductors 0 for connection either directly to the code announcing instruments, such as bells, horns or lights, but preferably leading to a suitable relay by which the operating circuit of the .code announcing instruments is established from a separate power outlet. Other conductors 0' may lead from the base, for operation from a watchmans button and still others shown at 0 for o ration from a telephone control relay, see ig. 12.

The code setting device is made up of one, two or more sectional or sub-units A A, etc. superposed to form' a stack, each sectional unit controlling a distinctive range of code signals. On top of the setting units may be mounted a base B mounting the commutator hereinafter referred to, through which the signal operating circuit is established in the 58%181106 determind by the actuated code key.

eferring to Figs. 4 and 5, a preferred construction of code setting sectional unit will now be described. Each unit referably comprises a generally rectangul sulating support panel 20, tightly fitted at its lateral edges in corresponding grooves of insulating ledge pieces 21, which extend beyond the front and back of the flat panel at 22. In corresponding longitudinal grooves 23 the insulating panel, parallel bus bars 24 preferably of copper, are secured. Metal bracket plates 25 and 26 extend along the free edges of the panel between the ledge pieces 21 and have angle shaped ends 30, each extending over the corresponding projecting corner or end 22 of the ledge 21, see Fig. 2.

Each of the metal bracket plates is stiffened by two angle bars 27 riveted thereto at 28 at the upper and lower edges thereof respectively. The insulating panel 20 has an in tegral central tongue 29 at each of the free edges thereof, lodged with little clearance in corresponding slots 31 in bracket plates 25 and 26 which sustain the middle of the long span of panel otherwise unsupported. The code setting circuits are established in a manner more fully described hereinafter, through key strips 32 constituting extensions of the keys 1:, and slidably mounted in the plates 25 and 26.

The assembly thus far described is enclosed in a metal frame, best shown in Fig. 2. The frame includes preferably a metal U-shaped piece, the arms 33 of which cover the outer faces of the ledges 21, the intervening part of the U constituting the rear wall 34 of the frame. A front plate 35 extends over the forward edges of the ledges and connects the free ends of the sides 33. A skeleton binding strap, shown in Fig. 11, includes a strip 37 extending over the rear wall -34 of the frame and has downwardly extending fingers 38 forming braces for the rear corners of the frame. The binding strap includes strips 39 extending along side walls 33 with fingers 40 at the forward ends thereof, forming corner braces which engage the front wall 35. Screws 41 threaded into the ends 22 of the ledges, secure the constituent parts of the frame about the insulating enclosure.

Each of the parallel key strips 32 which extends transversely across the bus bars 24, comprises a metal support strip 43 integral with the key shank and guided in corresponding slots 44 and 45 respectively in the front and rear metal bracket plates 25 and 26, the fronts ar molded inf of said key stems extending through the front plate and through the frame and operatively exposing the keys. Each of the metal support strips 43 of the keys has an upstanding hook 46, to which is anchored a coil spring 47,

the opposite end of which is anchored in a corresponding aperture 48 in the angle plate 27 of the front bracket plate, whereby the keys are normally urged to outermost position.

Preferably, the construction thus far de scribed is duplicated at opposite sides of the insulatin panel 20, each unit having two rows of eys, one coacting with the upper face of the panel and the other with the lower face thereof. The bus bars 24 are, accordingly, provided at both faces of the panel, as shown in Fig. 5. While the bus bars may be assembled to the support in any of a variety of ways, a simple and economical mode of assembly is by means of rivets 48', each of which affords a secure clamping as well as an electric conducting connection for two registering bus bars, on the opposite faces of the insulating panel.

Means is provided for retaining each key of the unit in operative position, after it has been depressed, the keys being preferably so interlocked that upon depression of any key, that previously depressed will be automatically cleared and returned to outermost position. For this purpose, a key lock plate 49 may be dis osed against the outer face of the front meta bracket plate 25 and mounted in place by studs 50 in the bracket plate extending through elongated slots 51 so as to admit of a limited longitudinal movement of the key lock plate 49, see Fig. 6. Plate 49 is normally urged toward the right by a coil spring 52 extending between a stud 53 fixed to the bracket plate 25 and another stud 54 fixed to the key lock plate.

As best shown in Figs. 2 and 9, each of the key strips 43 has a squared end 55 normally retained by the corresponding spring 47 in engagement with the inner face of the bracket plate 25 and has a shank portion 32 of reduced width therebeyond extending through a corresponding narrow slot 56 longitudinally through the key lock plate 49. Each of the keys has a ratchet tooth at its left edge provided with an inclined face 57 prd truding from the lock plate slot 56, the end of said tooth being squared off as at 58. Beyond said tooth is an inclined face 59 of greater length than inclined face 57, extending inward from the outer or key carrying shank 32 of the key strip.

By the construction described, as any key is depressed, the inclined face 57 will push the lock plate 49 to the left, against the resistance of spring 52, which will then snap said lock plate back over the squared end 58 of the tooth. As the key is pressed further inward the longer inclined face 59 will shift gaged by it, there y releasing said key, so

that it will immediately snap outward by the contraction of its spring 47. When the finger of the operator is removed from the key depressed, the spring 47 of the latter will then return said key to the limiting operative depressed position determined by the square face58 of the tooth, engaging the inner face of bracket plate 25 and thereby restraining the key strip in intermediate or operating position.

The specific bus-bar construction is shown in Figs. 7 and 8. ,Each bus bar 24 is provided with appropriate contact brushes or fingers f, f, preferably spring fingers formed integral therewith, extending rearward at right angles thereto. The key strips are provided each with identical contact plates 60, so formed and arranged that in normal inactive position of a key, the contact plate is out of electrical engagement with the various bus bar fingers f. If fingers on consecutive bus bars were disposed in alinement, these fingers would either have to be made shorter than is desirable. or the bus bars would have to be spaced further apart than shown, making a bulkier construction of apparatus. I have, accordingly, disposed the fingers of consecutive bus bars in staggered relation, as shown, that is, the fingers on bus bar 1-L2,' are in alinement with fingers on bus bars 3, 5 and 7, while the fingers of the intervening bus bars 2, 4 and 6 are in alinement but laterally spaced from those on the first mentioned bus bars. The spring fingers on each bus bar extend clea r of and beyond the succeeding bus bar and terminate, as shown, short of the bus bar next in order. The distance by which the bus bar fingers are staggered, corresponds to the width of the key strips, that is, each key strip contact 60 is of width such that its edges cover, for instance, contiguous fingers 61 and 62 of contiguous bus bars.

From the construction thus far described, it will be apparent that each key strip contact plate 60 should be of zigzag construction, as shown in Fig. 9, and as indicated in dot and dash lines on Fig. 7. Also, the notches 63 at the left edge of each key plate, as indicated in Fig. 7, clear the extremities of the bus bar spring fingers in alinement therewith, while. the notches 64 at the right side clear the extremities of the spring fingers of the alternate bus bars. When, however, a key is depressed and maintained in operative position, the contact plate 60 thereof is shifted so that the lateral lugs or tongues 63 and 64 are brought into operative coaction with the ends of those bus bar fingers or brushes f disposed in the range thereof.

' readily interpreted. The signal 3, for instance, is determined by a finger f on each of bus bars 1, 2 and 3, the signal 1-3, by a contact on bus bar 1, the omission of a contact onbus bar 2 and fingers on each of bus bars 3, 4 and5, so that in the travel of the commutator arm hereafter to be described, the omission of circuit closure for bus bar 2 represents a longer interval between the signal impulse due to contact 1 and the three successive impulses due to circuit closure at contacts 3, 4 and 5. It is unnecessary to indicate the precise arrangement of bus bar fingers, for each of the various codes within the range of my stack, since the principle is sufiiciently clear from the foregoing. The bus bar panel shown bein for the simplest signals, requires but seven slgnal making bus bars, as shown for producing the signals 1, 2, 3, 4, 5, 6, :7, 1-2, 13, 14. The insulatlng panel 20 is shown with nine bus bar carrying grooves, so that it may be used without modification in a code setting section for a range of signals of greater complexity. For instance, as suggested in the fragmentary view of Fig. 8, the signal 12-4 embodies fingers on the first, third, fourth, sixth, seventh, eighth and ninth bus bars, designated respectively by numeals 1*. f a 2, 221. and f"- The first bus bar 1L2T in each of the units making up the code setting stack has a finger f for each ofthe corresponding key strips, said finger, of course, determining the first and common signal impulse of each and every one of the code signals.

Each of the bus bar panels is also provided with a universal bus bar St preferably located at the extreme or rear groove of the system and provided with tooth or finger f for each key strip. This universal bus bar serves for establishing a circuit for starting the movement of the commutator arm in a manner which will appear more fully hereinafter. As described below, the commutator propulsion circuit is preferably automatitally opened after the cycle of code signals has been repeated a predetermined number of times, in order to avoid indefinite repetition of the code signal, also to dispense with the need for any special manual operation to cause the signals to cease sounding. For this purpose, as shown, the key contact plate 60 is provided with a narrow terminal contact tooth 65 which, when the key is pressed all the way in (that is, until the shoulder 66 of the carrying strip 43 contacts the rear bracket plate 26), will be in engagement with the corresponding finger f of the starting bus bar St." \Vhen the operators finger is removed from the key, the spring 47 urges the key strip outward to disengage the tooth 65 from finger 7, but, as hereinbefore described, to retain the key carrying strip 4.3 in operative or set position by the engagement of the squared end 58 of its tooth with the front bracket stop plate 25. As shown in the drawings, the signal controlling teeth 6364' of the key contact plate 60 are considerably wider than the starting teeth 65, so thatwhen a key is depressed to the extreme position in which operative contact is made with the starting bus bar St, those of the signalling contact bus bars corresponding to the code of the key will be operatively connected in circuit, the parts of those teeth 63, 64 nearest the front of the instrument then coming into engagement with the corresponding bus bar fingers, while, when the pressure of the operators finger is removed, the return of the spring 47 disengages the narrow starting tooth 65, from the starting bus bar St, but maintains the wider signal controlling teeth (SW-64 in engagement with the corresponding bus bar fingers. Thus, it will be seen that the operation of the signal is in no way dependent on a speedy or slow touch of the operator and the signal operation proceeds whether the universal or starting circuit is maintained closed or promptly opened.

For securing the key contact plates to the key strips, I connect each plate by means of rivets 60 upon a fiber board strip 75 which, in turn, is riveted at 76 at its outer and inner ends to the key strip support plate 43, the rivets 7 6 being, as shown, preferably beyond the ends of the contact plate.

Preferably the signal units thus far described are so constructed that two or more of them may be superposed to form a stack, such as indicated in the diagrammatic showing of Fig. 1, each unit governing a definite range of code signals and so that such superposition will inherently establish the electrical circuit for the various bus bars in the unit, Without the need for special wiring or separate connections from the source of power, to each of the units, or from each of the units separately to the apparatus controlled therefrom.

This result is accomplished by the simple expedient of forming a spring contact on one extremity'of each of the bus bars. The extremity, as best shown in Fig. 15, immediately beyond the end of securing rivet 48 of each bus bar is bent outward as shown, to form a finger extending freely along the corresponding ledge 21 of the insulating panel, the extremity being bifurcated at 71 and bent inward, as shown, substantially in the plane of the corresponding edge 33a of the enclosing frame 83. Preferably, as shown, the successive bus bars have their contact terminals at alternate ends of the frame, thereby maintaining a substantial gap between said free terminals. The terminals for the corresponding bus bars at opposite faces of the insulating panel extend from the same end of the panel, as best shown in Fig. 15, that for the upper bus bar extending upward and that for the lower downward. It follows that.when one of the sectional units is superposed upon another, the spring finger terminals 71 at the lower parts of the upper unit automatically enter into reliable circuit closin" relation with the u per terminals of the umt therebelow. Pre erably, as shown in Figs. 1 and 4, binding strap 37 for each enclosing frame extends above the upper edge of the frame 33-34, and the corner braces 38-40 terminate short of the lower edge of said frame, the lower part of the frame thus forming a pilot, to telescope into the sectional unit therebelow. The corner braces 38, 40

of the successive sectional frames come into end to end contact with each other and limit the approach of the parts and thereby guard against the bus bar terminals 71 being bent over by excessive pressure.

The circuit connections from the power line and to the controlled apparatus are preferably made in a distinct base unit shown separately in Fig. 12 and upon which rests the lowermost of the sectional setting units. The base unit preferably includes a bottom plate 77 resting on rubber support feet 78 which may be screwed to the table or bench. Bracket bars 7 9 are riveted along the sides of the base plate and form a support for the rectangular side wall frame 80, which is riveted as at 79' to the upstanding angles of the plates 79. The side wall is reinforced by a frame 81 enclosing the same and preferably of lesser height, in the rear wall of which are mounted bushings 82 for the power inlet and outlet conductors. The conductors are connected to terminal plugs (not shown) fitted into corresponding sockets or outlet boxes. The conductor parts within the base unit are held in position by cleats 82, and the ends of said conductors are connected to appropriate terminals disposed on insulating contact cleats 83 and 84 near opposite side walls of the base frame. The cleats 83 and 84 are secured to the base by screws 85 through the height thereof, threaded into the bottom panel, each extending through an intervening sheet of fiber 83.

In the illustrative embodiment shown, one

end of a power conductor 89 beyond the cleat 82' therefor, is connected by a terminal screw 88 to a terminal piece 87 near the forward end of the contact cleat 83. Terminal piece 87 secured to the contact cleat 83 by means of a screw 88', is formed of angle construction and has a flat surface 87' resting upon the upper edge of the cleat 83. The other power terminal 89 is connected by means of a screw 93 to a contact plate 94, in turn secured by a screw 95 to a face of the contact cleat 83. The contact plate 94 is connected by means of a conductor 96 to a terminal angle piece 86 similar to angle piece 87' and presenting a flat contact face 86' upon the contact cleat 83. The terminal angle piece hell or other instrument direct when no relay is employed. The other pole of the master relay is connected by means of the other conductor 90 to a terminal angle piece 92 similar to angle piece 86 and similarlymounted.

A terminal screw 91 serves to attach the conductor to said terminal angle piece and also serves simultaneously as an attachment for a terminal conductor 92w, through which a circuit may be closed for effecting a single impulse from a watchmans button. The opposite terminal 92w from the watchmans button is connected by terminal screw '93 to a contact plate 94 secured by mounting screw 95' to the contact cleat 83, said plate being electrically connected to the angle terminal plate 87 by means of a conductor 96. Terminal screw 93 also serves for mounting a conductor 9225 which leads to the telephone relay. Return lead 922? is connected by a terminal screw similar to those described to a terminal angle piece St, mounted on the contact cleat 84.

When the lowermost sectional setting unit is superposed over the base,the terminal 99 of the universal bus bar through which the first signal is effected comes into engagement with the overturned end 87 of terminal angle piece 87 and thereby establishes circuit therefrom to each of the corresponding bus bar terminals on each of the units of the stack. The horizontal part of the angle terminal piece St is contacted by the terminal end of the universal bus bar St in the lowest unit of the stack, through which the starting circuit is effected and from that unit by virtue of the engagement previously described between each of the corresponding bus bars of the entire stack, all of the starting bus bars on all of the units of the stack are electrically connected with said terminal piece. The terminal angle pieces 86' and 92 lead to corresponding terminals in the commutator or code operating unit. To this end, each of the units of the stack is provided with outstanding contact fingers 100, 101, which may be identical with those at the ends of the bus bars and may be secured to the insulating panel, each pair by an intervening rivet 102, see Fig. 7. It will be apparent that in the superposed stack, the current will pass from terminal 92 in the base, through the corresponding conducting fingers 100 upward to the uppermost stack, the current passing in each case by way of the connecting rivet 102 from one to the other of the fingers at opposite faces of each insulating panel.

The insulating plate B carrying the commutating or code operating unit is mounted within the frame of the uppermost unit of the setting stack. The bottom of said plate has a plurality of contacts 103 fixed therein,

tacts, circuits are established to the various contacts of the commutator and of the con v trol and operating elements therefor.

sectional code setting;

The base unit of Fig. 12 and the various units and the carrying plate B of the co e operating unit are all secured together by means of long screws 104 extending longitudinally through said carrying plate from near the corners thereof and through corresponding apertures in the ledges 21 of the insulating panels in each of the stack units. Screws 104 are threaded into correspondingly tapped upstanding posts 106 preferably cast integral with the bottom plate 77 of the base, see Fig. 13.

The key lock plates 49 of the various units in the assembled stack are interlocked by a vertical rod 107 extending through an outstanding eye 108 formed integral with each of said plates, so that the shifting of the corresponding lock plate due to the depression of any code setting key, will effect shifting of all of the other plates and thereby trip, clear or release a set key of the same or of any other unit in the stack, and permit the corresponding key spring 47 to return the key to outermost or .inoperative position. Each code setting key thus remains in set position and indicates the code last announced and can be tripped only by setting another code key.

For example the depressed key shown in Fig. 2 will be released by shifting movement of its lock plate 49 to the left, whenever any key in any other key section, or the same key section, is completely depressed. For it is quite apparent that any key in the stack when pushed all the way in will cause the maximum movement of its lock plate 49 to the leftwhenthe second inclined surface 59 of the key strip 32 engages the left hand edge of the slot 56 in the lock plate 49, and this movement being transmitted to all of the vertically arranged plates 49 through the rod 107, the last depressed key in the stack will be released.

Referring now to Fig. 16, there is shown in a developed view the manner in which circuit connections are established through the code setting units and the commutator or code operating unit, the details and mode of operation of which are more fully described in my copending application, filed Jan. 3, 1927, Serial No. 158,665, Patent No. 1,809,020, June 9, 1931. The top of the uppermost code setting unit A is shown in perspective, while the underside of the base B of the code operating unit is shown in elevation, it being evident from Fig. 1 that the base B rests upon and is received in the frame of the upperunit A when the whole device is assembled. As previously pointed out, the bus bars of each codesetting unit provides upward extending bent-overterminals 71 and these terminals are also numbered 1 to 9 consecutively, corresponding to the bus bars in Fig. 7. The unit A also rovides the terminals ST, 100 and 101, w ich are adapted to engage the contacts on the commutator base B marked ST, R and R respectively, when the base B is placed on the code unit.

As previously pointed out, Fig. 7 is a bottom view of a bus bar assembly so that the terminals 71 appear in reverse order from those shown in Fig. 16. However, when this unit is turned over from the position shown in Fig; 7 and placed face down on the base shown in Fig. 12, it is evident that the terminal on the bus bar 1 will engage the terminal piece 87, while the terminal on the bus bar St will engage the terminal piece marked ST. Furthermore, theidownwardly extending fingers 100 and 101 will engage the terminal pieces marked 86-R and 92-11 respectively.

As indicated in Fig. 16, the various contacts 103 in the base B are connected to a series of commutator contacts marked 0 to C inclusive, while the contact ST is connected to one terminal of a stepping magnet 128 which is adapted to impart a step-bystep movement to a commutator arm 120, as described in my above mentioned copending application.

While it is not believed necessary to burden the present application with a detailed description of the signal code sending device shown and described in my above mentioned copending application Serial. No. 158,665, enough of the signal callsystem is shown diagrammatically in Fig. 16 to make clear the utility of the code setting device of the present application. In Fig. 16 the key bearing the number 241 is shown as having been depressed thereby bringing the contact fingers on the bus bars designated .1, 2, 4, 5, 6, 7 and 9 into engagement with the key. As indicated the common bus bar 1 is permanently connected to one side of the source L so that when the key 241 is depressed all the way current will flow through the key to the starting bus bar St and from thence through the winding of the stepping magnet 128 back to the other side of the line. When the magnet 128 is energized the commutator arm 120 is turned through one step to bring its brush 124 into engagement with the first commutator contact 0 whereupon current will flow through the winding 185 of the master relay to cause one sounding of the'signals, as indicated by the arrows.

As fully set forth in the above mentioned copending application Serial No. 158,665 the magnet winding 128 is adapted to be intermittently energized by a make and break device to impart a step by step movement to the commutator arm 120, as long as the key I is depressed, so that the brush 124 is stepped around in successive engagement with the commutator contacts 0 to 0 inclusive. Ob-' viously the relay winding 185 will be energized also when the commutator contacts 0 0 c, 0", a, and 0 are energized to sound the signal 241. After the commutator arm 120 has been stepped around through one revolution it automatically comes to rest until another key is depressed, whereupon the cycle is repeated to sound the selected signal.

I claim:

1. A code setting unit comprising an insulating base, a plurality of parallel bus bars thereon, key strips extending transversely across said bus bars, said strips having identical contact plates thereon facing said bus bars, said contact plates having staggered lateral contact lugs, said bus bars having integral spring fingers corresponding to the code of the associated keys, said fingers free from contact with the key strip contact plates in the normal positions of the keys, the spring fingers of alternate bus bars being arranged for engagement by the lateral lugs of the key stem contact plates at one edge thereof, and the spring contacts of the intervening bus bars being arranged for engagement by the lateral lugs at the other edge of the key contact plates.

2. A code setting instrument comprising a plurality of units, each of said units including a frame, a plurality of parallel bus bars supported therein, a plurality of code setting keys protruding from said frame and having parallel key strips extending transversely of the bus bars, eachprovided with a contact plate facing the bus bars, the contact relations of each key and the portion of the bus bars transversed thereby corresponding to the code setting of the key, each of said bus bars having electrically associated therewith an upstanding terminal contact substantially flush with the edges of the open frame whereby a plurality of the units determining different codes may be superposed into a unitary code signalling set, with corresponding bus bars of each unit electrically connected together.

3. A stack of code setting units of similar construction, each determining a distinct range of code signals, each of said units including a key board, the keys of which have strips extending into the unit, each of said units having bus bars through which the code sequence of circuits is determined, each of said bus bars having outstanding terminal contacts, the terminals of the corresponding bus bars being in circuit-making engagement in the superposed stack, each of said units having a spring urged key-locking plate in front of the key board. the key stems having inclined teeth coacting with recesses in said plate, and a rod extending transversely through the locking plates of all of the units of said stack whereby the depression of any code key in any unit of the stack will effect release of any other depressed key in the same or in any ot er unit of the stack.

4. In a code setting unit, an insulating support panel having bus bars lodged in corresponding parallel grooves in opposite faces thereof, and rivets through the panel securing corresponding bus bars against opposite faces of the panel, said bus bars having each an upstanding yielding terminal at one on thereof and unitary therewith.

5. A code setting unit comprising an insulating support panel having bus bars lodged in corresponding parallel grooves in opposite faces thereof, rivets through the panel securing corresponding bus bars against opposite faces of the panel, key support bracket plates extending along opposite edges of said panel, said panel having an integral relatively wide tab projecting from an edge thereof into a corresponding slot in one of said bracket plates.

6. A code setting stack comprising a plurality of substantially identical units, each unit covering a distinct range of code signals, each of said units including an insulating panel having a plurality of parallel bus bars on opposite faces thereof, an enclosing frame for the panel of height greater than the thickness thereof, a key board atthe front of said frame and key strips extending through the frame for coaction with the bus bars, each of said bus bars having an outwardly extending terminal at one end thereof whereby the various bus bars will be automatically disposed in circuit in the superposed stack.

7. A code setting unit comprising a molded insulating generally rectangular panel having ledge bars at opposite ends thereof extending beyond the lateral edges of the panel, bus bars extending longitudinally of the panel in parallel relation and secured thereto, each of said bus bars having an upstanding finger reversely bent at its outer end and substantially flush thereat with the outer edge of said ledge, key support brackets extending along the edges of said panel and secured at said ledge bars, a frame extending about said panel and key stems extending through said brackets and presenting a key board in front of said frame, said key stems having contact plates for coaction with said bus bars.

8. A code setting unit comprising a molded insulating rectangular support panel having ledges at opposite ends thereof extending above and below the main surface of the panel, bus bars extending longitudinally of said panel along opposite faces thereof and secured thereto, each of said bus bars having at one end thereof an upstanding finger extending along the corresponding ledge and having a contact portion substantially flush with the free edge of said ledge, key support brackets along the edge of said panel, a frame extending about the panel and the key carrying brackets,'a double row key board at the front of said frame, key stems associated with said keys, said stems extending in two groups transversely across the bus bars at opposite faces of the support panel.

9. A code signalling stack comprising a support base having power inlets and control outlets and including terminals for the same, a stack of code determining units, each unit corresponding to a distinctive range of code signals, each of said units including a frame of larger dimensions than the base frame and having terminals therein registering with the terminals in the support base, each of said units having bus bars therein, each provided with a terminal in a predetermined relation whereby the units of the superposed stack when assembled are automatically disposed in circuit making relationship, and a commutator support base mounted on top of the uppermost unit of the stack and having terminal contacts registeringwith those from the control base.

10. A code signalling stack comprising two or more key-set units in superposed relation, the keys of each unit embracing a distinctive range of code signals, each unit having electric terminals disposed in circuit making relation with respect to the contiguous units by the mere assembly of the units in correct superposed relationship, each of said units comprising a rectangular frame having a binding strap thereabout, the binding strap including integral tabs forming corner braces of the frame the length of the binding strap extending beyond the edge of the frame whereby each frame can be secured in engagement with the contiguous edge of the next frame by the binding strap, and the corner braces enter into end to end relationship in the superposed assembled stack.

Dated this 4th day of November, 1926.

HERBERT BURDICK. 

